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March is, 1924. 1,487;129

L. H. WHEELER VACUUM PRODUCING MEANS FOR FUEL FEED DEVICES Filed June 12. 1922 MTNESS. v [EDNA-RD H. whim/ Byk/s JJTm/s/Em Patented Mar. 18, 1924.

UNITED STATES LEONARD H. WHEELER, OI CHICAGO, ILLINOIS, ASSIGNOR TO STEWART-WARNER SPEEDOIVIIE'IEF. CORPORATION GINIA. '5

, 01 CHICAGO, ILLIIEOIS, A CORPORATION OF VIB- VAGUUIKLPRODUGING FOR FUEL-FEED DEVICES.

Application filed June 12, 1922.

To (:U whom it may concern:

Be it known that I, LEONARD H. IVHnnLnn, a citizen oi? the United States, residing in the city of Chicago, in the county of Cook and the State of Illinois, have invented certain new and useful Improvements in Vacuunr Producing Means for Fuel-Feed Devices, of which the following is a specification, reference being had to the accompanying drawings forming a part thereof.

The purpose of this invention is to provide an improved means for producing the vacuum in a vacuum fuel feeding device for internal combustion engines, particularly for the purpose of preventing the drawing over of the vapor of the fuel into the vacuum producing means. It consists in the elements and features of construction shown and described, as indicated in the claims.

In the drawings 2- Figure 1 is a side elevation of a portion of an engine and the vacuum fuel feed device for serving the same, except with the device embodying this invention, the invention being shown in outline except as to the intake manifold and carburetor.

Figure 2 is a section axial with respect to the vacuum producing means embodying the invention, showing the same in conjunction with the vacuum tank, section being made axially with respect to the connections of said device with the tank.

Figure 3 is a vertical section axial with respect to its communicating passages, of a modified form of pumping or vacuum producing device.

Figure 41: is a detail section axial with respect to its communicating passages, of a valve fitting at the junction of the two suction lines which may be employed alternatively or conjunctively in communicating the suction for producing vacuum in the vacuum feed device.

Figure 5 is a detail partly diagrannnatic view showing a manually operable means for selectively bringing into operation either one of two suction producing means.

In the drawings the intake manifold is indicated at A, the carbureter at A B is the vacuum tank, so called, comprising a vacuum chamber B and service chamber, B C is a vacuum producing pumping device moun*- ed upon and communicating with the vacuum chamber of the vacuum tank, B. D is the Serial No. 567,571.

oil circulating pump for circulating lubricant from the crank case, IV, on the engine on the parts to be lubricated. E is the in take pipe leading from the rank case, IV, to the pinup, D. E is a cut off and regulating valve in the pipe, E. E is a T-fitting for connecting it with the pipe, E, and supply pipe, F, F which leads to the operating side of the pump, D, for communicating suction to the piston chan'iber, C to operate the piston, C for producing suction upon the opposite side of the piston, that is, for producing partial vacuum in the chamber, 0 which is connected by a pipe, G with the vacuum chamber, B of the vacuum tank, and by a pipe fitting, C, with the service chamber, 15, and specifically with the annular upper portion, B thereof, a check valve, h, at the inlet connection of the pipe, G with the chamber, 0 for inlet to said chamber, and the check valve, ill, at the communication of said chamber, 0 with the pipe fitting, 0, opening for outlet or discharge from said chamber, 0 into the service chamber, B at the annular part, B thereof. The piston, C of the pump, C, is held normally at its ully inthrust position by a compression spring, C, which yields or is compressed upon the retraction of the piston when partial vacuum is produced in the chamber, C The relief valve, C being seated inwardly having its stem, O protruding into the chamber, C to a distance to cause it to be encountered by the piston, C in its retraction stroke, just before the limit of said retraction, whereby said valve is opened and atmosphere admitted to oifset and neutralize the suction by which the piston has been retracted, and cause it to be immediately thrust bacr inward by the reaction of the spring. It will be understood that the alternate re traction and inthrust of the piston will pump air out of the vacuum chamber, B and discharge it into the service chamber, B and by this means the vapor which may be drawn from the vacuum chamber, by the suction stroke is immediately passed back into the service chamber, B where it becomes available by condensation for supplying the carbureter. By this means only atmospheric air is drawn into the source of suction, which in the construction thus far described is an oil pump by which the air passes into the oil circulation Without injury.

It will usually be regarded as preferable to derive suction from the intake manifold of the engine whenever and so long as that suction is adequate for maintaining the fuel supply. It is therefore desirable that the pumping device shown for producing the vacuum in the vacuum tank should be connected for operation by suction from the intake manifold, as well as for operation from the oil pump; and this is easily accomplished by the construction shown, having the pipe L, leading from the intake manifold into connection through the valve fitting, G, with the pipe, F leading to the pump. The valve fitting, G. in which the pipe, F is connected both with the pipe, F, and with the pipe, L, is constructed for automatically causing the pump to be operated by the higher suction, from whichever of the two sources it is derived ;that is, so as to be operated by the suction from the intake manifold whenever that suction is higher than that derived from the oil pump, and to be operated by the suction from the oil pump whenever that is higher than the suction derived from the manifold. is effected by means of the check valves, N and N both normally seating downward by gravity, the former at the entrance of the pipe, F, and the latter at the entrance of the pipe, L, to said fitting, G. It will be understood that if suction operating through the pipe, F, is the greater, this suction will produce in the passage, 9 of the fitting, (i, a higher degree of vacuum than that which will exist in the pipe, L, and thereby the valve, N will be held seated; and similarly, if the suction operating in the pipe, L, is greater than that operating through the pipe, F, there will be produced in the passage, 9, a higher degree of vacuum than that which will exist in the pipe, F, and thereby the valve, N, will become seated.

It may be considered desirable under some circumstances that instead of the automatic selection as between the two sources of suction which will result from the eniployment of the valve fitting, G, as above described, the selection should be at the will of the driver; and for that purpose there may be employed, as shown in Figure 5, a three-way valve, T, at the junction of the pipes, F and L, and from which the pipe, G leads to the pump. The operation of this valve by the driver for selecting the source of suction will be obvious without further description.

In Figure 3 is shown a modified form of suction pump in which an expansible and contractible member, M, of the sylphon type is substituted for the piston, C of This Figure 1. The member, M, divides the in terior of the casing, G, into two chambers, C and 0 preferably being sealed to the bottom wall of the casing as shown. In operation the suction produced in the chamber, C through its connection with the oil circulating pump or the engine intake manifold causes the expansion of the member, M, against the pressure of the swing, C while at the same time air and vapor are drawn into the chamber, 0 from the vacuum chamber, B through the connection, C hen the member, M, expands sulliciently, it trips open an atmosphere inlet valve like that shown at C, in Figure 2, thus relieving the suction in the chamber, C whereupon the n'lember, M, under the influence of the spring, C, or aided thereby, contracts discharging air and vapor from the chamber, 0 into the service chamber, B

I claim 1. In combination with a bi-cameral vacuum fuel feeding device, a suction pump having its intake connected with the primal or vacuum chamber of the fuel feeding device and its discharge connected with the secondary or service chamber of the same.

2. In the construction defined in claim 1, foregoing, the reciprocating element of the pump being provided with a spring which reacts for the discharge movement, and the pump chamber at the opposite side of the reciprocating element from that in which the inlet and discharge connections are made having a suction connection and a valve controlled air inlet, the valve at said inlet being normally seated and pro-- vided with means for opening it at the limit of the suction stroke of the reciprocating element.

3. In combination with an internal combustion engine and a vacuum fuel feeding device for supplying the carburete' from a low source, a suction pump which is suction operated, having its chamber at one side of the reciprocating element connected for intake with the vacuum chamber and for discharge with the service chamber of the vacuum fuel feed device; the chamber at the other side of the reciprocating element being connected for suction with the intake manifold of the engine and provided with a valve-controlled atmosphere inlet whose valve is normally seated, and is opened by the suction stroke of the reciprocating cle ment at the limit of said stroke.

In testimony whereof, I have hereunto set my hand at Chicago, Illinois, this 7th day of June, 1922.

LEONARD H. WIIEELER. 

